On the instability of gas bubbles in a liquid to crushing when exposed to a weak pressure wave

Abstract

The dynamics of a pressure wave in a bubbly liquid in cylindrical and conical channels is considered on the basis of numerical modeling. The tendency of gas bubbles to split behind the wave front due to the development of Rayleigh-Taylor and Kelvin-Helmholtz instabilities is analyzed. In the first case, the Bond number is the criterion for the instability of bubbles; in the second case, it is the Weber number. It has been found that with the same initial state of the bubble system, the destruction of bubbles due to Rayleigh-Taylor instability can occur at lower amplitudes of the impacting pressure wave than in the case of the Kelvin-Helmholtz instability mechanism. The study shows the possibility of the crushing of bubbles in a narrowing channel by low-amplitude pressure waves, which, when propagating in a cylindrical channel, do not change the dispersion of the gas phase. We have established the maximum threshold dispersion of the mixture at which the crushing of bubbles by waves of the considered amplitude does not occur.